75 results about "Fries rearrangement" patented technology

Polycarbonates containing low or undetectable levels of Fries rearrangement products and comprising repeat units derived from one or more of resorcinol, hydroquinone, methylhydroquinone, bisphenol A, and 4,4′-biphenol have been prepared by the melt reaction of one or more of the aforementioned dihydroxy aromatic compounds with an ester-substituted diaryl carbonate such as bis-methyl salicyl carbonate. Low, or in many instances undetectable, levels of Fries rearrangement products are found in the product polycarbonates obtained as the combined result of a highly effective catalyst system which suppresses the Fries reaction and the use of lower melt polymerization temperatures relative to temperatures required for the analogous polymerization reactions using diphenyl carbonate.

A fluorescent article is disclosed comprising a polymer matrix comprising a polymer having in its backbone repeating units of a U.V. light absorbing moiety, or a moiety capable of being transformed by photo-Fries rearrangement into a U.V. light absorbing moiety, the matrix further comprising a fluorescent dye. The matrix affords surprisingly improved fluorescence protection as compared to prior fluorescent articles having only U.V. light absorbing additives.

A laser weldable composition made from a process of melt blending a combination of a partially crystalline thermoplastic polyester component such as poly(butylene terephthalate), an amorphous thermoplastic polycarbonate having a Fries rearrangement of greater than 150 to 10,000 ppm, and a filler such as glass fiber. The laser weldable composition has a polycarbonate aryl hydroxy end-group content of at least 300 ppm and provides improved near infrared transmission at 960 nanometers. A method welding components made from the weldable composition and welded articles made therefrom are also disclosed.

The invention provides a new preparation method of drug Pranlukast for treating asthma. The new preparation method includes the specific steps that with 2-aminophenol-4-sulfonic acid as a starting material, a key intermediate 3-amino-2-hydroxyacetophenone is prepared by means of acylation, Fries rearrangement and deprotection, then reacts with 4-(phenylbutoxy)benzoic acid, and then is subjected to condensation with ethyl 1H-tetrazole-5-acetate, and finally preparation is achieved through ring closing under the acidic condition. Compared with the prior art, the raw material used for the new preparation method is low in price and easy to obtain, industrialization of a process can be achieved easily, and the obtained final product is high in purity; and no dangerous process exists, equipment is simple, and the route is novel.

The invention provides a method for preparing a p-hydroxy phenyl ethyl ketone compound through Fries rearrangement reaction under catalysis of an acidic ionic liquid. The method comprises the following steps of: directly adding phenyl acetate to the ionic liquid, wherein the dosage of the ionic liquid is 10%-40% of the mole number of oligomers; next, reacting for 12-18 hours at a temperature ranging from 60 to 120 DEG C, thus obtaining p-hydroxy phenyl ethyl ketone without o-hydroxy phenyl ethyl ketone type product through extraction, drying and reduced pressure distillation. The ionic liquid applied to the method is used as a solvent and a catalyst, and is high in catalytic activity and selectivity; the dosage of the catalyst is low and the reaction yield is high; the use of other organic solvent and toxic catalyst is reduced, so that the corrosivity of the catalyst to equipment is reduced; the aftertreatment is simple and convenient.

The invention provides a preparation method for 4-methoxy-1,3-phthalic acid. 4-methoxy-1,3-phthalic acid is key intermediate for preparation of an anti-platelet aggregation drug picotamide (with a trade name of plactidil). According to the preparation method, 4-methoxy-1,3-phthalic acid is prepared from the starting raw material p-methylphenol or o-methylphenol through esterification, Fries rearrangement, methylation, oxidation and acidification. Compared with traditional preparation methods, the preparation method provided by the invention has the advantages of low equipment investment, simple operation, quick reaction, high yield, low synthesis cost, greatly reduced environmental pollution and the like, and is particularly suitable for large-scale industrial production.

The present invention provides a method for manufacturing a liquid crystal display device including a photo-alignment film and capable of sufficiently improving the display quality. The method for manufacturing a liquid crystal display device of the present invention is a method for manufacturing a liquid crystal display device including a photo-alignment film. The method for manufacturing a liquid crystal display device successively includes a step (1) of forming on a substrate a film from a photo-alignment-film material that contains a solvent and a polymer including a photo-functional group that is capable of causing at least one chemical reaction selected from the group consisting of photodimerization, photoisomerization, and photo-Fries rearrangement; a step (2) of pre-heating the film to evaporate the solvent; a step (3) of irradiating the pre-heated film with polarized light; and a step (4) including an operation of main-heating the polarized-light-irradiated film at multiple temperatures from a lower temperature to a higher temperature. The liquid crystal display device is of an in-plane switching mode or a fringe field switching mode in each of which a pre-tilt angle is substantially 0°.

The invention provides a process for preparing 3-benzyloxy-4-butylaniline hydrochlorides, which comprises using m-aminophenol as raw material, carrying out butanoylation reaction and Fries rearrangement, obtaining 2-butyryl-5-butyramidophenol, under the action of alkali, reacting 2-butyryl-5-butyramidophenol with benzyl halides, obtaining 2-butyryl-5-butyramidophenyl benzyl ether, hydrolyzing to obtain 3-benzyloxy-4-butyryl benzeneamine, finally carrying out Huangminglong reduction reaction to obtain 3-benzyloxy-4-butylaniline hydrochlorides.

A flurorescent article is disclosed in which a U.V. light screening layer comprising a polymer having in its backbone repeating units of a U.V. light absorbing moiety, or a moiety capable of being transformed by Photo-Fries rearrangement into a U.V. light absorbing moiety, is disposed in operative screening relation to a layer containing a fluorescent colorant. The U.V. light screening layer affords surprisingly improved fluoresence protection as compared to prior U.V. light screening layers having only U.V. light absorbing additives.

The invention provides a preparation method for 5-fluorin-2-hydroxyacetophenone. The preparation method comprises the following steps of: performing double esterification on amino groups and phenolic hydroxy in one step by taking amino-phenol as a raw material; performing Fries rearrangement under the condition of aluminum chloride/sodium chloride; heating a hydrolyzate after performing fluorine diazotization to obtain finished 5-fluorin-2-hydroxyacetophenone. The preparation method has the advantages of low prices of raw materials, relatively mild reaction conditions, total yield of up to 54.5 percent and industrial production application value.

The invention discloses a new preparation method of a key intermediate, namely 3-amino-2-hydroxyphenylacetone, for preparation of Pranlukast. The new preparation method comprises the following main steps: taking 2-aminophenol-4-sulfonic acid as a starting raw material, and carrying out acylation, Fries rearrangement, hydrolysis and deprotection, so that 3-amino-2-hydroxyphenylacetone is obtained. Compared with the prior art, the new preparation method disclosed by the invention has the advantages that the used raw materials are cheap and easily available, technology can easily realize industrialization, and the obtained final product is high in purity; no danger technology is adopted, and equipment is simple; and route is novel, and synthesis route is short.

The invention relates to a synthesizing method and preparing process for seselin and the derivatives. The method takes substituted hydroxyphenol as a raw material, and after Pechmann reaction, acetylation, Fries rearrangement, cyclization, reduction and dehydration, the seselin compound can be obtained. The method has the advantages of simple operation of each step, controllable conditions, easily obtained reagent, convenient purification, single product and high yield. The synthesizing route overcomes the defects of low yield and being difficult to remove isomers of the existing methods. The seselin and the derivatives which are taken as the important bioactive substance and medical intermediate have good application prospect in anti-inflammatory, anti-fungus and anti-tumor aspects, particularly playing a key role in synthesizing candidate anti-HIV agents. The synthesizing route and the method have high application value and wide application prospect.

The invention relates to a synthetic method for para-methyl catechol diacetoxyl dimethyl ester. The method uses paracresol as an initial raw material to synthesize the para-methyl catechol diacetoxyl dimethyl ester into a target compound through acetylation reaction catalyzed by acid, Fries rearrangement reaction of phenolic ester, Dakin oxidation reaction of 2-hydroxy-5-methyl acetophenone and direct etherification reaction of para-methyl catechol. The total yield of the whole reaction is more than 70 percent, and the purity of the product is more than 98 percent. The method of the invention has the characteristics of easily-obtained raw materials, mild reaction condition, low equipment requirement, simple operation, low production cost, little side reaction, simple post treatment, and the like. Therefore, the synthetic method of the invention is a method suitable for industrialized production.

The invention discloses a method for synthesizing 4-methyl catechol. The method comprises the steps of carrying out acylation reaction on p-cresol as a starting materia to obtain p-cresyl acetate, carrying out Fries rearrangement reaction in a high-boiling-point inert solvent to obtained 2-hydroxy-5-methyl acetophenone, alkalifying, forming a salt, oxidizing at a low temperature, after the reaction is completed, reducing the reaction solution, acidifying, extracting and concentrating to obtain a crude product and distilling the crude product to obtain the pure 4-methyl catechol. The method disclosed by the invention is environmental friendly, available in raw materials, mild reaction conditions, low requirements on equipment, simple operation, low production cost, less side effects and high yield and is suitable for industrial production.

The present invention provides a method for manufacturing a liquid crystal display device including a photo-alignment film and capable of sufficiently improving the display quality. The method for manufacturing a liquid crystal display device of the present invention is a method for manufacturing a liquid crystal display device including a photo-alignment film. The method for manufacturing a liquid crystal display device successively includes a step (1) of forming on a substrate a film from a photo-alignment-film material that contains a solvent, a polymer including a photo-functional group that is capable of causing at least one chemical reaction selected from the group consisting of photodimerization, photoisomerization, and photo-Fries rearrangement, and a polymer including a polyamic acid backbone and free from the photo-functional group; a step (2) of pre-heating the film to evaporate the solvent; a step (3) of irradiating the pre-heated film with polarized light; and a step (4) of main-heating the polarized-light-irradiated film. The liquid crystal display device is of an in-plane switching mode or a fringe field switching mode in each of which a pre-tilt angle is substantially 0°.

The invention relates to the field of organic chemical synthesis, and discloses a method for preparing 2,3-dihydroxytoluol serving as a medicinal intermediate. In the method, the 2,3-dihydroxytoluol as the medicinal intermediate is synthesized by using o-cresol as a raw material and by three fine processing steps of esterification, Fries rearrangement and Dakin reactions. The 2,3-dihydroxytoluol is an important fine chemical engineering intermediate, and has the wide applications in medicinal industry; and at present, there are fewer reports on synthetic methods, and the synthetic methods arenot suitable for industrial production. In the method, the total yield of the process is 30 percent. In the method, the raw material is cheap, and the reaction conditions are mild. Thus, a process for synthesizing the 2,3-dihydroxytoluol is developed.

The invention relates to a synthesis method for raw material drugs of dicamba. The synthesis method for the raw material drugs of dicamba comprises the following steps: taking 2,5-dichlorophenol as a starting material, carrying out esterification under the actions of an organic solvent and an organic esterification reagent to generate 2,5-dichlorophenol acetate; dissolving 2,5-dichlorophenol acetate in the organic solvent and adding a catalyst to generate Fries rearrangement, thus generating 3,6-dichloro-2-hydroxyacetophenone; making 3,6-dichloro-2-hydroxyacetophenone react with a methylating reagent under the action of an acid-binding agent to obtain 3,6-dichloro-2-methylacetophenone; synthesizing dicamba (3,6-dichloro-2-methoxybenzoic acid) under the action of 3,6-dichloro-2-methylacetophenone. The synthesis method for the raw material drugs of dicamba disclosed by the invention is simple in process, highly available in raw materials and the catalyst, low in cost, simple in post-treatment operation, low in environmental pollution, high in safety of reaction operation, high in reaction yield, good in product quality and favorable for industrialization.

The invention discloses an improved Rhodomyrtone preparation method, and relates to the technical field of chemical synthesis, the improved Rhodomyrtone preparation method effectively optimizes each reaction condition and post-treatment mode in the Friedel-Crafts acylation, methylation, reduction reaction, Michael addition and acid-mediated cyclization reaction, and Fries rearrangement reaction processes, and improves the yield of Rhodomyrtone. The problems that silica gel column chromatography separation needs to be used, a large number of explosive and toxic solvents are used, the total yield is low, and the method is only suitable for preparation on the scale of dozens or hundreds of milligrams in an existing synthesis method are solved, the obtained Rhodomyrtone does not need silica gel column chromatography separation, the total yield is high (34.6%), the purity is high (99.8%), and the method is suitable for amplified-scale preparation.

The invention discloses a synthetic method for p-hydroxybenzaldehyde. The synthetic method comprises the following steps: with phenol and formic acid as raw materials, subjecting the raw materials toan esterification reaction under the action of a catalyst A so as to produce phenyl formate; and subjecting phenyl formate to a Fries rearrangement reaction under the action of a catalyst B so as to produce p-hydroxybenzaldehyde. According to the invention, the conversion rate of the raw materials is high, product yield is high, and the method is novel method for preparing p-hydroxybenzaldehyde from phenol and formic acid; and phenol and formic acid undergo the esterification reaction under the action of the catalyst A so as to produce phenyl formate, phenyl formate undergoes the Fries rearrangement reaction under the action of the catalyst B so as to produce p-hydroxybenzaldehyde, and then recrystallization and purification are carried out, so product purity can reach 99% or more, and overall product yield is as high as 95%. The method uses widely available raw materials and cheap and easily available catalysts, and is simple in reaction process, free of severe requirements on production equipment, low in equipment investment and convenient for industrial application.